Enhanced reversibility of the electrochemical Li conversion reaction with MgH2–TiH2 nanocomposites

Nanostructured metallic hydrides are promising anode active materials for the next generations of Li-ion batteries due to their high capacities, adapted working potential and low polarisation. In the present study, nanocomposites made of yMgH₂ and (1 ? y)TiH₂ with molar composition y = 0.2, 0.5 and 0.8 were prepared by mechanical milling of elemental metal powders under hydrogen pressure. Microstructural analysis by X-ray Diffraction (XRD) and Transmission Electron Microscopy (TEM) shows the co-existence of the two hydrides at the nanoscale with average crystallite sizes comprised between 4 and 11 nm. Galvanostatic and cyclic voltammetry experiments have been performed to investigate the reversibility of the conversion reaction between both hydrides and lithium. All nanocomposites can be fully lithiated for the first discharge, but the reversibility of the reaction strongly depends on the composition. No reformation of any hydride occurs for the TiH₂-rich composite (y = 0.2), TiH₂ is only partially reformed for the equimolar composite (y = 0.5) and both MgH₂ and TiH₂ hydrides are recovered at different extents for the Mg-rich one (y = 0.8). A high reversibility (almost 80%) of TiH₂ is attained in the latter composite with a promising capacity retention (70% over ten cycles) by cycling within a restricted potential window.     

Food Derived Bioactive Peptides and Intestinal Barrier Function

A wide range of food-derived bioactive peptides have been shown to exert health-promoting actions and are therefore considered functional foods or nutraceuticals. Some of these actions are related to the maintenance, reinforcement or repairment of the intestinal barrier function (IBF) whose role is to selectively allow the absorption of water, nutrients and ions while preventing the influx of microorganisms from the intestinal lumen. Alterations in the IBF have been related to many disorders, such as inflammatory bowel disease or metabolic syndrome. Components of IBF are the intestinal epithelium, the mucus layer, secretory immunoglobulin A and cells of the innate and adaptive immune systems. Here we review the effects of food derived bioactive peptides on these IBF components. In vitro and in vivo effects, both in healthy and disease states, have been reviewed. Although limited, the available information indicates a potential for food-derived peptides to modify IBF and to contribute to disease treatment, but further research is needed to better isolate responsible peptides, and to help define their mode of action.     

A Hyperbolic Theory for Advection-Diffusion Problems: Mathematical Foundations and Numerical Modeling

Linear parabolic diffusion theories based on Fourier’s or Fick’s laws predict that disturbances can propagate at infinite speed. Although in some applications, the infinite speed paradox may be ignored, there are many other applications in which a theory that predicts propagation at finite speed is mandatory. As a consequence, several alternatives to the linear parabolic diffusion theory, that aim at avoiding the infinite speed paradox, have been proposed over the years. This paper is devoted to the mathematical, physical and numerical analysis of a hyperbolic convection-diffusion theory.     

Studies on the stability of Kathon® CG/ICP Microbicide in alpha olefin sulfonate Based systems

Kathon^® CG/ICP Microbicide (Rohm & Haas Co.) which contains 1.5% 5-chloro-2-methyl-4-isothiazolin-3-one and 0.35% 2-methyl-4-isothiazolin-3-one as active ingredients has been found to be a highly efficient antimicrobial preservative for formulated products. However, its use has been contra-indicated for formulations containing certain anionic surfactants, especially AOS, because of the suspected presence of residual bisulfite ion added to remove residual hypochlorite remaining at the end of the bleaching process. It has been found that sulfite ion is not stable in the complex mixture of components in commercially produced AOS. AOS samples tested, whether bleached or not, contained residual reducing capacity, but of a sufficiently low redox potential as to not affect Kathon^® CG/ICP Microbicide stability. Alternative analytical methods for analysis for bisulfite in AOS and other surfactant systems are discussed. A new HPLC method for determination of Kathon^® CG/ICP Microbicide level in formulated products was developed.     

On the Logic of Theory Change: Contraction without Recovery

The postulate of Recovery, among the six postulates for theory contraction, formulated and studied by Alchourrón, Gärdenfors and Makinson is the one that has provoked most controversy. In this article we construct withdrawal functions that do not satisfy Recovery, but try to preserve minimal change, and relate these withdrawal functions with the AGM contraction functions.     

Evolutive Introns: A Non-Costly Method of Using Introns in GP

We proposed a new strategy to explicitly define introns that increases the probability of selecting good crossover points as evolution goes on. Our approach differs from existing methods in the procedure followed to adapt the probabilities of groups of code being protected. We also provide some experimental results in symbolic regression and classification that reinforced our belief in the usefulness of this procedure. Collateral effects of Evolutive Introns (EIs) are also studied to determine possible modifications in the behavior of a classical Genetic Programming (GP) system.     

Flexible and efficient computer‐aided design tool for advanced comb‐line rectangular waveguide filters

A very flexible and efficient computer‐aided design (CAD) tool, specifically suited for advanced comb‐line rectangular waveguide filters, is presented in this work. The developed software tool, which makes use of a full‐wave analysis technique based on the Boundary Integral—Resonant Mode Expansion method, allows loading the considered comb‐line resonators with any number of radially symmetrical partial‐height metallic posts. The implemented CAD tool also allows dealing with coupling windows of arbitrary cross‐section, thus drastically enhancing the flexibility of the CAD process. The excitation of the analyzed components, which is performed using generalized coaxial probes, has also been integrated in the implemented software tool, thus achieving a full‐wave electromagnetic characterization of the whole component. Furthermore, a novel simple procedure to efficiently connect all the obtained wide‐band matrices is proposed. To validate the accuracy and efficiency of this novel CAD tool, several new designs concerning advanced band‐pass comb‐line waveguide filters are presented. The accuracy of the developed CAD tool has been successfully validated by comparing the obtained results with numerical data provided by a commercial tool based on the finite‐element method. © 2015 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:696–708, 2015.     

Scenario-based virtual network infrastructure management in research and educational testbeds with VNUML

Virtual machine technologies have evolved during the last 40 years from mainframe to commodity (x86) systems. Although these techniques are nowadays quite mature in data center environments (consolidation, service continuity, etc.), scenario-based virtual infrastructure management tools keep evolving in research and educational areas. In this work, one such tool is described, Virtual Network User Mode Linux (VNUML), which has been successfully used during the past few years to help researchers and educators to build testbeds in a wide range of innovative network environments (such as IPv6 IX design and third-generation networks). Such application cases are detailed in this paper, assessing the soundness and flexibility of the tool. However, in spite of these successful applications, several challenges remain to be solved in virtual scenario management (distributed management, decoupling from any particular virtualization technique, and alignment with industry standards), and the way they are being addressed as part of VNUML’s evolution is also discussed.